My b2evolution Version: 3.3.3

Does anyone know of a plugin or some option that allows the setting of "valid date" for a post. In other words, you post something and put in a "start time/date" and "end time/date" so the post is only active during that time period? If not, that would be an awesome plugin.

The second option that would be nice would be the ability to randomly load a post from a pool of posts when the page loads. A check box that says something like "add this post to rotation pool #1", then you could do a post from "pool #1" chosen either at random or in sequence every time the page loads. Anyone know of anything along these lines?